Silver halide supersensitized photographic emulsions

ABSTRACT

A SIHLVER HALIDE LIGHT-SENSITIVE PHOTOGARPHIC EMULSION CONATINING AT LEAST ONE SENSITIZING DYE REPRESENTED BY THE FOLLOWING FORMULA 1:   2-((3-R2,5-R4-2,3-DIHYDROBENZOXAZOL-2-YLIDENE)=CH-C(-A)=   CH-),3-R1,5-R3-BENZOXAZOLIUM (X1(-))(N-1)   WHEREIN R5 AND R6 EACH REPRESENTS AN ALKYL GROUP OR A SUBSTITUTED ALKYL GROUP; R7 AND R8 EACH REPRESENTS AN ALLKYL GROUP, A SUBSTITUTED ALKYL GROUP, AN OPTIONALLY NEUTRALIZED SULFOALKYL GROUP OR A SUBSTITUTED ALKYL GROUP HAVING AN OPTIONALLY NEUTRALIZED SULFO GROUP WHEREIN THE ALKYL MOIETY THEREOF IS ATTACHED TO THE SULFO GROUP THEREOF THROUGH AT LEAST ONE ALKOXYL GROUP OR DIRECTLY CONNECTED WITH A HYDROXY GROUP AND THE SULFO GROUP; AT LEAST ONE OF SAID R7 AND R8 REPRESENTING A CARBAMYLALKYL GROUP OR SAID SULFOALKYL GROUP OR SAID SUBSTITUTED ALKYL GROUP HAVING A SULFO GROUP; R9 R10, R11 AND R12 EACH REPRESENTS A HYDROGEN ATOM, AN ALKYLSULFONYL GROUP; AN ALKYLSULFAMOYL GROUP, A N-DI-SUBSTITUTED AMINOSULFONYL GROUP, AN ALKYLCARBAMOYL GROUP, A N-DI-SUBSTITUTED CARBAMOYL GROUP, A CYANO GROUP, A TRIFLUOROMETHYL GROUP OR A HALOGEN ATOM; X1- REPRESENTS AN ACID ANION; AND M IS 1 OR 2; M BEING 1 WHEN AT LEAST ONE OF SAID R7 AND R8 IS THE SUBSTITUENT HAVING A SULFO GROUP; AT LEAST ONE OF SAID R5 AND R6 BEING SAID SUBSTITUTED ALKYL GROUP OR AT LEAST ONE OF SAID R7 OR R8 BEING SAID SUBSTITUTED ALKYL GROUP HAVING AN OPTIONALLY NEUTRALIZED SULFO GROUP WHEN ALL HOOF SAID R9, R10, R11 AND R12 ARE A HYDROGEN ATOM, A HALOGEN ATOM OR MIXTURES THEREOF; WITH THE PROVISO THAT WHEN SAID R3 AND R4 ARE SIMULTANEOUSLY PHENYL, SAID R9, R10, R11 AND R12 MAY NOT SIMULTANEOUSLY BE BYDROGEN OR CHLORINE.   (X1(-))(M-1)   YLIDENE)=CH-CH=CH-),3-R7,5-R11,6-R9-BENZIMIDAZOLIUM   1-R5,2-((1-R6,3-R8,5-R12,6-R10-2,3-DIHYDROBENZIMIDAZOL-2-   WHEREIN A REPRESENTS AN ALKYL GROUP HAVING FROM 1 TO 4 CARBON ATOMS; R3 REPRESENTS HALOGEN ATOM, A HYDROXY GROUP OR A PHENYL GROUP; R4 REPRESENTS A HYDROGEN ATOM, A HALOGEN ATOM, A PHENYL GROUP, A HYDROXYL GROUP, AN ALKYL GROUP, OR AN ALKOXYL GROUP; R1 AND R2 EACH REPRESENTS AN ALKYL GROUP OR AN OPTIONALLY NEUTRALIZED SULFOALKYL GROUP; X1- REPRESENTS AN ACID ANION; AND N IS 1 OR 2; SAID N BEING 1 WHEN AT LEAST ONE OF SAID R1 AND R2 IS A SULFOALKYL GROUP; AND AT LEAST ONE SENSITIZING DYE REPRESENTED BY THE FOLLOWING FORMULA II:

June 4, 1974 U E sHlBA ETAL 3,814,609

SILVER HALIDE SUPERSENSITIZED PHOTOGRAPHIC EMULSIONS Filed April 25,1973 3 Sheets-Sheet l 3 A g g A r WAVE LENGTH m mp June 4, 1974 KE|5UKE$H|BA ETAL 3,814,609

SILVER HALIDE SUPERSENSITIZED PHOTOGRAPHIC EMULSIONS 3 Sheets-Sheet 2Filed April 25, 1975 FIG. 2

Mwe length m u bmmqm gc m FIG. 3

Wave length m u FIG.4

Wbve length m June 1974 KEISUKE SHIBA ET AL 3,814,609

SILVER HALIDE SUPERSENSITIZED PHOTOGRAPHIC EMULSIONS Filed April 25,1975 3 Sheets-Sheet 13 RELATIVE SPEED I I I l l i WAVE LENGTH m u UnitedStates Patent 3,814,609 SILVER HALIDE SUPERSENSITIZED PHOTOGRAPHICEMULSIONS Keisuke Shiba and Akira Sato, Kanagawa, Japan, as-

US. Cl. 96-124 20 Claims ABSTRACT OF THE DISCLOSURE A silver halidelight-sensitive photographic emulsion containing at least onesensitizing dye represented by the following formula I:

I l; (X -)n1 R wherein A represents an alkyl group having from- 1 to 4carbon atoms; R represents a halogen atom, a hydroxy group or a phenylgroup; R represents a hydrogen atom, a halogen atom, a phenyl group, ahydroxyl group, an alkyl group, or an allcoxy group; R and R eachrepresents an alkyl group or an optionally neutralized sulfoalkyl group;X represents an acid anion; and n is l or 2; said n being 1 when atleast one of said R and R is a sulfoalkyl group; and at least onesensitizing dye represented by the following formula II:

wherein R and R each represents an alkyl group or a substituted alkylgroup; R and R each represents an alkyl group, a substituted alkylgroup, an optionally neutralized sulfoalkyl group or a substituted alkylgroup having an optionally neutralized sulfo group wherein the alkylmoiety thereof is attached to the sulfo group thereof through at leastone alkoxyl group or directly connected with a hydroxy group and thesulfo group; at least one of said R and R representing a carbamylalkylgroup or said sulfoalkyl group or said substituted alkyl group having asulfo group; R R R and R each represents a hydrogen atom, analkylsulfonyl group; an alkylsulfamoyl group, a N-di-substitutedaminosulfonyl group, an alkylcarbamoyl group, a N-di-substitutedcarbamoyl group, a cyano group, a trifluoromethyl group or a halogenatom; X, represents an acid anion; and m is 1 or 2; m being 1 when atleast one of said R and R is the substituent having a sulfo group; atleast one of said R and R being said substituted alkyl group or at leastone of said R or R being said substituted alkyl group having anoptionally neutralized sulfo group when all of said R R R and R are ahydrogen atom, a halogen atom or mixtures thereof; with the proviso thatwhen said ice R and R are simultaneously phenyl, said R R R and R maynot simultaneously be hydrogen or chlorine.

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is acontinuation-in-part application of our co-pending application Ser. No.276,999, filed Aug. 1, 1972, now abandoned, which is, in turn, acontinuation-in-part of our earlier co-pending application Ser. No.47,702, filed June 19, 1970, and now abandoned.

BACKGROUND OF THE INVENTION Field of the invention The present inventionrelates to a super-sensitized gelatino silver halide photographicemulsion. More particularly, it relates to a silver halide photographicemulsion for color photographic light-sensitive materials, the greensensitive range of the photographic emulsion having been spectrallysensitized.

DESCRIPTION OF THE PRIOR ART It is well known that spectralsensitization is animportant technique for the production oflight-sensitive materials and in particular, the technique is anindispensable one for the production of color photographiclightsensitive materials. The color reproduction or the quality of thecolor image of a color photographic light sensitive material isparticularly influenced by the spectral sensi tivity or the distributionof spectral sensitivity of a greensensitive region having a high visualsensitivity. Since even a slight difference in the spectral sensitivityof the greensensitive region has a large influence on the quality oflight sensitive materials, those engaged in the production of lightsensitive materials have carefully studied the slight diflerences in thespectral sensitivity in the greensensitive region of a photographicemulsion.

It is known that the spectral sensitivity of light sensitive materialsis influenced by the properties of the silver halide emulsion used, suchas its composition, crystal habit, grain size, manner of chemicalripening, the pH and the silver ion concentration of the silver halide;the kind of binder to be used; and the nature of additives such as anantifoggant, a stabilizer, a wetting agent, a coupler for colorphotographic light-sensitive material, a dispersing agent for thecoupler, a plasticizer, and a hardening agent. In many cases, they actto reduce or instabilize the spectral sensitivity.

The spectral sensitivity of light sensitive materials is also largelyinfluenced by the chemical structure of the sensitizing dye used forspectrally sensitizing silver halide photographic emulsions, and, inaddition, is largely influenced by the manner of adding the sensitizingdye to the photographic emulsion, such as the addition amount thereof,the time of adding the dye, and the period when the photographicemulsion is allowed to stand after the addition of the sensitizing dye.A sensitizing dye may be used alone, but in many cases two or moresensitizing dyes are used for obtaining a desired spectral sensitivitydistribution. In the latter case, it is rare' that the use of thecombination of two or more sensitizing dyes gives an additive spectralsensitivity. That is to say, in many cases, the spectral sensitivityobtained by using a combination of two or more sensitizing dyes is lowerthan the spectral sensitivity obtained by using each of the sensitizingdyes alone, and this is called anti-sensitization.

0n the contrary, it sometimes happens that the use of a combination oftwo or more sensitizing dyes gives a superadditive higher sensitivity,which is called super-sensitization. In order to obtain a combination oftwo or more sensitizing dyes providing such a super-sensitization, eachdye must be carefully selected, and it is known that the.

selection of a combination of sensitizing dyes from the dilference intheir chemical structures is quite difiicult. In other words, it isimportant to find a combination of two or more sensitizing dyes givingthe super-sensitization action, i.e., giving a desired spectralsensitivity distribution and a high spectral sensitivity.

The green sensitizing technique for color photographic light-sensitivematerials has been investigated by many persons but conventionaltechniques have various defects.

For example, US. Pat. No. 3,397,060 to Schwan et a1. discloses thesuper-sensitization of green-sensitive silver halide emulsions by addingthereto a combination of:

(a) An oxacarbocyanine dye which does not contain more than one phenylsubstituent, and

(b) A benzimidazolocarbocyanine dye.

A primary object of this invention is to provide a highsensitive silverhalide photographic emulsion having less of a color stain caused by thesensitizing dyes remaining therein after development, and wherein thesensitivity in the wave length region of from 500 m to 530 m has beenincreased.

More specifically, it is an object of the present invention to providean improvement over the Schwan et al. reference mentioned above.

The formation of the above-mentioned color stain depends not only on thechemical structure of the sensitizing dye but also on the physical stateof the sensitizing dye in the silver halide emulsion, e.g., itsaggregation state, the interaction of the sensitizing dye with a couplercontained in the emulsion, and in particular, the interaction thereofwith other sensitizing dyes to be incorporated in combination with it.

The present inventors have further discovered that by selecting acombination of specific sensitizing dyes, the formation or color staincan be reduced by the coaction thereof. It is difiicult to selectivelyincrease the sensitivity in the green-sensitive region, and particularlyin a wave length region of from 500 mp. to 530 my. This is due to thefact that there are only a small number of sensitizing dyes capable ofabsorbing light of this wave length region on silver halide crystalswhile giving high sensitivity.

The present inventors have found that the above-mentioned object of thepresent invention can be attained by using a combination of sensitizingdyes capable of super-sensitizing by finely dividing the J-aggregate ofeach other.

SUMMARY OF THE INVENTION The silver halide photographic emulsions ofthis invention contain at least one sensitizing dye represented by thefollowing formula I and at least one dye represented by the followingformula II:

A represents a lower alkyl group (i.e., having 1 to 4 carbon atoms;

R represents a halogen atom (e.g., chlorine, bromine, etc.), a hydroxygroup, or a phenyl group (e.g., phenyl, tolyl, etc.);

R represents a hydrogen atom, a halogen atom (e.g., chlorine etc.), aphenyl group, a hydroxyl group, an aralkyl group, an alkyl group or analkoxyl group;

R and R each represents an alkyl group or an optionally neutralizedsulfoalkyl group (e.g., fl-sulfoethyl, 'y-sulfobutyl, etc.);

X represents an acid anion group of the type usually employed in thefield of carbocyanine dyes (e.g., halogen,

'4 thiocyanate, perchlorate, benzylsulfonate, benzenesulfonate,methylsulfate, ethylsulfate, p-toluenesulfonate, etc.); and

n is 1 or 2; n being 1 when one of R and R is a sulfoalkyl group;

R and R each represents an alkyl group (e.g., methyl, ethyl, propyl,etc.) or a substituted alkyl group where the substituent is vinyl,acetoxy, hydroxy, etc. (e.g., vinylmethyl, acetoxypropyl, hydroxyethyl,etc.);

R and R each represents an alkyl group, a substituted alkyl group (thesubstituent being vinyl, acetoxy, hydroxy, carbamyl, etc.) an optionallyneutralized sulfoalkyl group (e.g., a-alkyl group having an optionallyneutralized sulfo group wherein (in the case of the alkoxy-substitutedalkyl group) the alkyl moiety thereof is attached to the sulfo groupthereof through 1 or 2 alkoxyl groups (i.e., -alkyl (alkoxyl) SO wherep=1 or 2), or (in the case of the hydroxy-substituted alkyl group)directly connected with a hydroxy group and the sulfo group (i.e.,-alkyl-S0r),

such as 2-(3-sulfopropoxy)ethyl, 2-[3-(3-sulfopropoxy) ethoxy]ethyl or2-hydroxy-3-sulfopropyl; at least one of said R and R being acarbamylalkyl group, said sulfoalkyl group or said substituted alkylgroup having a sulfo p;

R R R and R each represents a hydrogen atom, an alkylsulfonyl group(e.g., methylsulfonyl, ethyl sulfonyl, etc.), an alkylsulfamoyl group(e.g., methylsulfamoyl, ethylsulfamoyl, etc.), an N-di-substitutedaminosulfonyl group (e.g., morpholinosulfonyl, etc.), an alkylcarbamoylgroup (e.g., ethylcarbamoyl, etc.), an N-dissubstituted carbamoyl group(e.g., morpholino carbamoyl, etc.), a cyano group, a trifluoromethylgroup, or a halogen atom (e.g., chlorine, bromine, fluorine, etc.);

X; represents an acid anion group as defined for X above; and m is l or2; m being 1 when at least one of R and R is a substituent having asulfo group;

With the proviso that when R R R and R are simultaneously hydrogen orhalogen or mixtures thereof, at least one of R and R is said substitutedalkyl group or at least one of said R and R is said carbamylalkyl groupor said alkoxy or hydroxy-substituted alkyl group having an optionallyneutralized sulfo group; and

With the further proviso that when said R and R are simultaneouslyphenyl, said R R R and R may not simultaneously be hydrogen or chlorine.

BRIEF DESCRIPTION OF THE DRAWINGS The figures are spectrograms showingthe relative sensitivity (i.e., speed) of various photographic filmsemploying super-sensitizing dye combinations according to the presentinvention as well as prior art combinations and individual dyes alone.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Among the sensitizingdyes represented by formula I according to the present invention, thesensitizing dye in which R and R are simultaneously a phenyl group hasthe disadvantage that a J-aggregate is liable to form and the formationof color stain is increased, but this drawback of the dye of formula Iis overcome by using the dye in combination with the sensitizing dyerepresented by the formula H (see the second proviso in the Summary ofthe Invention).

'lypical examples of the sensitizing dyes which may be used in thepractice of the present invention are shown below:

The above-mentioned sensitizing dyes used in this invention are knownand they are described in the specifications of U.S. Pat. No. 3,268,334,British Pats. Nos. 840,- 223 and 742,112; Japanese Patent PublicationNo. 4931/ 68; Belgian Pats. Nos. 697,009, 704.296, 648,981 and 660,650;German Pat. No. 1,180,241; British Pats. Nos. 975,504, 980,234,1,077,984 and 1,084,435; Belgian Pats. Nos. 673,554, 668,014 and669,133; and Japanese Patent Publications Nos. 14,1 12/ 65 and 23,467/65. Furthermore, other sensitizing dyes which may be used in thisinvention may also be synthesized from the descriptions in theabovementioned patents.

The sensitizing dyes of the present invention may be incorporated intothe silver halide emulsions as solutions in water or a Water-solubleorganic solvent such as methanol or ethanol.

The sensitizing dye represented by formula I and the sensitizing dyerepresented by formula H may be dissolved in the solvents separately andthese solutions may then be added to the silver halide emulsionseparately or as a mixture thereof. The amounts of the sensitizing dyesare extremely influenced by the nature of the silver halide emulsion tobe used, but ordinarily the amount thereof is preferably from 1 10- moleto 1 10 mole per 1 mole of silver halide. Also, the preferable molarconcentration ratio of the amount of the sensitizing dye represented byformula I to the amount of the sensitizing dye represented by formula IIis from 1:10 to :1.

The silver halide emulsion which may be used in this invention maycontain, as the silver halide, silver iodobromide, silver bromide,silver chlorobromide, or silver iodochlorobromide. The silver halideemulsion used in this invention is generally a gelatino silver halideemulsion but silver halide emulsions other than those employing gelatinmay be employed; e.g., those employing polyvinyl alcohol, alginic acidpolymer, polyvinyl imidazole, polyvinyl pyrrolidine, or copolymersthereof. The gelatino silver halide emulsion of this invention mayfurther contain any of the above-mentioned polymers.

The present invention can also be applied to a silver halide emulsioncontaining, e.g., a photographic dye, an antifoggant, a stabilizer, asensitizer, a coupler, a plasticizer, a wetting agent, etc. The silverhalide emulsion of this invention may be applied to a proper supportsuch as a paper, a glass plate, a cellulose triacetate film, apolyethylene terephthalate film, other plastic films, a resinlaminatedpaper, a resin-coated paper, or a synthetic paper.

The invention may be illustrated further by reference to the followingexamples, which are only illustrative, and not limiting, in nature:

EXAMPLE 1 1 kg. of a silver iodobromide (silver iodide: silver bromide 4mo]: 96 mol) prepared by a conventional manner was melted and afteradding thereto definite amounts of solutions of sensitizing dyes havingconcentrations shown in Table 1, the mixture was stirred. After allowingthe mixture to stand for 15 minutes at 40 C., in order to show clearlythe effect of the reduction of sensitivity by the presence of a coupler,200 ml. of a 5% alkaline aqueous solution of the magenta coupler havingthe structure shown below was addedto the mixture and" thereafter the pHof the mixture was immediately adjusted to 6.5 using citric acid whilestirring. Thereafter, a hardening agent and saponin were added to theemulsion and the finished emulsion was uniformly applied to a film to athickness of 7.0 microns.

Chemical structure of the magenta coupler:

Water m 500 Metol g 0.1 Potassium pyrosulfite .g 1.4 Anhydrous sodiumsulfite ..g.. 38 Hydroquinone -g-.. 6 Sodium carbonate monohydrate g22.5 Citric acid g 0.7 Potassium bromide g 0.9

Water added to make 1000 ml.

The thus-developed photographic film was then fixed. The densities ofthe strips thus processed were measured using an S-type densitometermade by Fuji Photo Film Co., Ltd., whereby the relative spectralsensitivity (green sensitivity) was obtained. The results are shown inTable 1.

On the other hand, the spectrogram obtained by using a spectrographcontaining a reflection-type diffraction grating, made by Narumi Shokai'as Spectrograph GR-2 type (trademank), is shown in FIG. 1. Curve 1represents the film having only sensitizing dye I-D therein, curve 2,

only sensitizing dye II-B, and curve 3, a combination thereof,respectively. The sensitizing dyes and the correspondence thereof to thesamples are. shown in the remarks column in Table 1.

TABLE 1 Amount of Amount of Relative dye added dye added green (molarmolar sensi- Test No. Dye cone), ml. Dye cone), ml. tivity Fog Remarks40 (5X10- 60 0. 07 38 30655600 13% 3'35 1 (m) so (HA) 40 159 0: 70 0. 080 91 0. 09

Samples 0! Curve 2.

141 71 83 2:: 23 a 0 (1B) D) 20 7o 40 a5 20 1x10-= a1 0. 06 40 0 43 0.087 (IC) 80 (HD) 60 0.08 40 20 (5x10- 115 0.08 40 40 132 0.09

40 0 87 0.06 Samples 0! Curve 1. a (ID) 80 (m3) 0 100 0.00

40 20 (5x10- 141 o. 00 e 40 40 141 0.07 Samples 0! Curve 3.

v 40 so 200 0.07

3 (m) 28 22 a am) 20 71 0108 40 0.09

m a (m) :8 28 is: (HF) 20 03 0:09 40 78 0.10

1 (ID) :8 0X10") i8 (5X10- 3 3 (HG) 20 0a 0 10 40 75 0.12

40 axle- 20 (5x10- 1;;1 0.00 {59 m-n :3 as 40 80 0.00

EXAMPLE 2 TABLE 2 Amount of Amount 0! The samples produced as n Example1 were SUbjCCtCd dye added dye added to the wedge exposure as 1n Example1 and then de- 60 (molar cone. (molar cone. Relative veloped in a colordeveloper having the composition g D o dye soluor dye solu- E e tlou ml.D e tlou m1. sensit is shown below for 12 minutes at 20 C.:0.5 C. Thereyy m y after the samples thus developed were subjected to a first 5 igg8.1; fixing, a first water washing, bleaching, a second fixing, 40 2(5X10-4) 100 0:20 and a second water washing. The densities of thestrips 13 i 3% 8%; thus processed were measured through a green filterto ob- 2 03 0I17' tain the relative green sensitivities shown in Table2. 4

The composition of color developer: G. EPLE 3 N,n-diethylaminoparaaminoaniline sulfate 2.0 70 Samples were prepared as in Example. 1employing the Sodium sulfite 2.0 dyes in the amounts shown in Table 3below. The relative Sodium carbonate monohydrate 50.0 spectralsensitivity (green sensitivity) was measured in the Hydroxylaminehydrochloride 15 same manner as in Example 1 and the results are shownPotassium bromide 1.0 in Table 3. FIGS. 2, 3 and 4 are spectrograms forthe dye Water added to make 1000 ml. combinations shown in the Remarkscolumn in Table 3.

TABLE 3 Amount oi Amount of Relative dye added dye added green (molar(molar sensi- Test No. Dye eonc.),ml. Dye conc.),ml. tivity Fog Remarkss (1x10 a 100 0.06 Fig. 2 (curve 1). 14 (ID)---- (HK)---- 20 (sxur) 8:Fig. 2 (curve 3).

40 100 0.11 Fig. 2 (curve 2).

40 158 0. 09 Fig. 3 (curve 5). 2o (5x10- 7e 0. 09

40 80 0. 09 Fig. 3 (curve 4).

33 il i3? 8&3 Fl 4( 6) a 0 16 20 (5x10- 71 0.08 g

38 1 3 Fl 4 11: 7 .v 0 6 17 20 (5X10'*) 31 0.14 g v 23 20 iii 3' r1 5 ua a- 0 [V6 18 "[20 (5X10"4) 94 0.11 g

.......... 40 117 0. 11 Fig. 5 (curve 9).

In Table 3, the dyes designated 1, H and B are Formula II disclosed inUS. Pat. No. 3,397,060 Schwan et a1., and 5 R5 s have the followingstructures: i Dye 1 R0 R10 0 0 /CCH=CH-CH=O\ 62H R11 n \e con=b-on=c NN/V \N 01 in (Xr)m-1 its 2 E wherein R and R each represents an alkylgroup or a CHmSO' )ssoaH substituted alkyl group where the substituentis vinyl, Dye B acetoxy or hydroxy; R and R each represents an alkyl 92H02H group, a substituted alkyl group wherein the substituent I 1 isvinyl acetoxy, hydroxy or carbamyl, an optionally neu- 01 tralizedsulfoalkyl group, or an alkoxyor hydroxy-sub- Cl stituted alkyl grouphaving an optionally neutralized 40 sulfo group of the formula-a1ky(alkoxyl) S0 or 01 c1 N N alk l-so (dHmsor (dHmSO H H Hrespectively, where p is 1 or 2; at least one of said R and R being acarbamylalkyl group, said sulfoalkyl group or N N said substituted alkylgroup having a sulfo group; R 01 01 R R and R each represents a hydrogenatom, an C-CH=CH-CH=C alkylsufonyl group, an alkylsulfamoyl group, anN-di- H 0 0 GEN C1 substituted amino-sulfonyl group, an alkylcarbamoyl NN group, an N-di-substituted carbamoyl group, a cyano (HmsoaNa group, atrifluoromethyl group, or a halogen atom; X

wherein A represents an alkyl group having from 1 to 4 carbon atoms; Rrepresents a halogen atom, a hydroxy group or a phenyl group; Rrepresents a hydrogen atom, a halogen atom, a phenyl group, a hydroxylgroup, an alkyl group, or an alkoxyl group; R and R each represents analkyl group or an optionally neutralized sulfoalkyl group; X representsan acid anion; and n is 1 or 2; said 11 being 1 when at least one ofsaid R and R is a sulfoalkyl group; and at least one sensitizing dyerepresented by the following formula II;

represents an acid anion group; and m is l or 2, m being 1 when at leastone of R and R is a substituent having a sulfogroup; with the provisothat when R R R and R are simultaneously hydrogen or halogen or mixturesthereof, at least one of R and R is said substituted alkyl group or atleast one of said R and R is said carbamyl group or said alkoxyorhydroxy-substituted alkyl group having an optionally neutralized sulfogroup; and with the further proviso that when said R and R aresimultaneously phenyl, said R R R and R may not simultaneously behydrogen or chlorine.

2. The silver halide photographic emulsion of claim 1, wherein thesubstituted alkyl group of R R R and R is acetoxypyropyl, hydroxyethyl,carbamylethyl or allyl; wherein said .alkoxyor hydroxy-substituted alkylgroup having an optionally neutralized sulfo group is a 2-(3-sulfopropoxy) ethyl group, a 2-[2-(3-sulfopropoxy) ethoxy] ethyl groupor a 2-hydroxy-3-sulfo-propy1 group; wherein the N-di-substituted aminosulfonyl group is morpholino sulfonyl; and wherein the N-di-substitutedcarbamoyl group is morpholinocarbamoyl; wherein the halogen atom of R RR and R is a chlorine atom; wherein said alkyl group of A is ethyl.

13 3. A silver halide photographic emulsion containing a sensitizing dyeof the formula and at least one sensitizing dye represented by formulaII as in claim 1.

4. A silver halide photograph emulsion as in claim 3, wherein thesensitizing dye represented by formula II is a dye of the formula (ii-H:ih l 5. A silver halide photographic emulsion containing a sensitizingdye of the formula and at least one sensitizing dye represented byformula II as in claim 1.

6. A silver halide photographic emulsion as in claim wherein thesensitizing dye represented by formula H is a dye of the formula 7. Asilver halide photographic emulsion containing a sensitizing dye of theformula and at least one sensitizing dye represented by formula II as inclaim 1. 7

8. A silver halide photographic emulsion as in claim 7 wherein thesensitizing dye represented by Formula II is a dye of the formula 1 4)11 4) zfld (CHiCHa) (0 CHzCH!) (0 ca 3 16 11 11):

9. A silver halide photographic emulsion containing a sensitizing dye ofthe formula M'Hifia/ g/ \N and at least one sensitizing dye representedby formula II as in claim 1.

10. A silver halide photographic emulsion as in claim 9, wherein thesensitizing dye represented by formula H is a dye of the formula 11. Asilver halide photographic emulsion as in claim 9, wherein thesensitizing dye represented by formula H is a dye of the formula 12. Asilver halide photographic emulsion as in claim 9, wherein thesensitizing dye represented -by formula II is a dye of the formula 13. Asilver halide photographic emulsion containing at least one sensitizingdye represented by formula I in claim 1 and a sensitizing dye of theformula I11 cn=c Il \N or (331m) 2 a) (OCIHI)SOI 14. A silver halidephotographic emulsion as in claim 1, which contains from 10- to 10- moleof each of the sensitizing dyes of formulae I and H per 1 mole of silverhalide.

15 w 16 15. A silver halide photographic emulsion as in claim and atleast one sensitizing dye represented by formula I 1, wherein the molarconcentration ratio of the sensitizing as claimed in claim 1. dye offormula I to the sensitizing dye of formula II is 20. A silver halidephotographic emulsion as in claim within the range 1:10 to 10:1. 19wherein the sensitizing dye represented by formula I 16. A silver halidephotographic emulsion as in claim 5 is a dye of the formula: 1, whereinat least one magenta coupler is incorporated therein.

17. A silver halide photographic emulsion as in claim 0 O 16, whereinsaid magenta coupler is represented by the 1111s formula C-CH=O--CH=Cman o-cg, or I,&/ \N 01 v (cmusoa- (oHmsor ;NH: S0311 NH:

References Cited UNITED STATES PATENTS 3,348,949 10/1967 Bannert et al.96-124 18. A photographic silver halide light-sensitive element3,397,060 8/1968 Schwan et al 96124 comprising a support having thereonat least one layer 3,506,443 4/1970 Motter 96-124 containing the silverhalide emulsion of claim 1. 3,663,210 5/1972 Sato et al. 96-124 19. Asilver halide photographic emulsion containing 3,713,835 1/ 1973 Sato etal. 96-124 3. sensitizing dye of the formula:

J. TRAVIS BROWN, Primary Examiner (ihHr 72 N\ /N 01 01 96-100, 137

C-CH=CHCH==C US. Cl. X.R.

